Can the functions support `win_length` in stft and melspectrogram?

[yuikns]

It is really a great job. However, could it been possible that support "win_length" args?

Here are the references:

• https://librosa.org/doc/0.9.1/generated/librosa.feature.melspectrogram.html
• https://librosa.org/doc/0.9.1/generated/librosa.stft.html

we may required to pass this variable to stft, and change get window getter

[ewan-xu]

I will add this feature when I have time recently